unable to contact all domain controllers - when continuing int set

Hi

I have 2 DC's Win 2000, one exchange 2000, New SBS 2003 Premium SP2
I have followed kb 884453 until i got stuck on point 13

with this error

in event log there are no errors on any server
replication is working fine etc.

SBSBPA doesn't show errors any other then ones related to unfinished
installation likei guess:
Microsoft integration registry key does not exist
Windows SBS SP1 not installed ( further down i can find that i have sp2
installed )
ExchangeVdir does not exist ( Exchange is not installed yet am i thinking
right ?? )
Internet connection sharing should be disabled
shared memory protocol not enabled

in information i have a list of statements
that sbs can ping all domain controllers
that there are existing win2000 dc's
that sbs holds all roles etc


I need to resolve this problem ASAP because i need to install exchange

i found exactly the same problem on experts exchange website
and the resolution was that MS engineers remotely changed something in sbs
to stop it coming up with this error

please tell me what do i need to check
to provide more information